diff --git a/docs/Gemfile b/docs/Gemfile
index 91ceacd3..ee114290 100644
--- a/docs/Gemfile
+++ b/docs/Gemfile
@@ -1,2 +1,3 @@
 source 'https://rubygems.org'
-gem 'github-pages', group: :jekyll_plugins
\ No newline at end of file
+gem 'github-pages', group: :jekyll_plugins
+gem "webrick"